Network standards organizations such as WiMAX Forum and 3GPP have both been investigating single radio handover from/to their networks. The IEEE 802.21c Task Group also is working on single radio handover standard. Generally, the advantages of single radio handover are reduced peak transmission power requirement and less sophisticated signal filtering of the source/target receiver radio from the target/source transmission radio, resulting in lower cost of the multiple radio device.
In a single radio handover, since the device (also commonly referred to a user equipment, mobile station, mobile node, subscriber, user, terminal, and the like) is using a single radio, it is not free to use the radio tuned to the target radio network when the radio is tuned to the source radio network. Therefore, the source radio network is the only reliable means to transmit/receive. It is then necessary to perform as many functions as possible for making the handover using the source radio network prior to handover. One such function is the discovery of available networks. Generally, without using the target radio network, location information of the user equipment alone may be used to determine the candidate target network(s) for handover.